Development of new biomimetic bioinks useful in 3D bioprinting of cartilage tissue

Resum

Articular cartilage is a tissue with important functions in preserving and enabling locomotion. However, it has limited intrinsic repair capacity when is damaged, which requires medical intervention. Among new strategies for the treatment of cartilage pathologies, bioprinting is being explored as a promising option, allowing the creation of tissue-like engineered substitutes by controlled deposition of cells and biomaterials (bioink). In this attempt, the selection of a suitable bioink, in terms of biological and mechanical properties, is crucial. In this study, we developed biomimetic bioinks useful for cartilage tissue bioprinting. One of these consisted of natural polymers that resemble the native environment of cartilage, hyaluronic acid (HA) and alginate. Its rheological characterization indicated to have properties required to be applied in 3D bioprinting, including easy printability and jellying abilities. Moreover, biological assays demonstrated high bioactivity, improving the ability of chondrocytes to proliferate, facilitating phenotype maintenance for long-term and promoting cartilaginous-specific matrix deposition. The other bioink, with a composition more similar to the chondrogenic environment of embryological development, was based on a matrix derived from Mesenchymal Stem Cells in culture. It exhibited suitable mechanical properties, including shear thinning behavior, good shear recovery, and gelling abilities. Biocompatibility and bioactive properties were also demonstrated. Results from gene expression and histological assays indicated that this new biomimetic bioink was capable to induce chondrogenesis of MSCs and cartilage tissue formation both in vitro e in vivo.